During the refining of molten metal, and particularly of molten steel, the measurement of parameters of the molten metal such as temperature, or oxygen by expendable immersion devices or the taking of molten metal samples by such devices must, due to the temperatures involved, be carried out by operators situated a significant distance from the molten metal. Because of the distance and the temperature, the parameter sensing element is secured, generally by some form of cement into one end of a long hollow heat resistant or insulating tube. In use, a manipulator consisting usually of a metal tube or pipe with a receptacle for the parameter sensing element mounted at one end is inserted into the heat resistant tube until the parameter sensing element engages the receptacle at the end of the manipulator. The manipulator is longer than the heat resistant tube and typically terminates in a handle section to facilitate the immersion into and withdrawal from the molten metal of the parameter sensing element.
Because of the length of the expendable immersion device and of the manipulator it is standard procedure for the operator to grasp the heat resistant tube to mount the expendable immersion device onto the manipulator. Because of the need to adequately and properly engage the parameter sensing element and the receptacle located in the end of the manipulator, the operator at times slides the expendable immersion device onto the manipulator with such force applied to the heat resistant tube that the cement holding the parameter sensing element into the end of the heat resistant tube is cracked or partially broken away. If this condition is not noticed by the operator, molten metal will flow into the interior of the heat resistant tube upon immersion into the molten metal and destroy the receptacle and those parts of the manipulator that are generally protected by the heat resistant tube.
It is an object of this invention to eliminate the possibility of dislodging or partially dislodging the parameter sensing element from the end of the heat resistant tube when an expendable immersion device is mounted on a manipulator.
It is another object of this invention to insure that the parameter sensing element is in proper engagement with the receptacle in the end of the manipulator while avoiding the possibility of dislodging the element when mounting an expendable immersion device on a manipulator.
It is a further object of this invention to provide an improved receptacle for the manipulator to provide easier field replacement of the receptacle in the manipulator.